JP2014233918A - Lamination device and method for producing multilayer film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lamination device in which generation of a curl can be prevented when films different in elastic modulus are stuck to each other and to provide a method for producing a multilayer film.SOLUTION: The lamination device is constituted so that an endless metallic belt 12 is hung over between a first heat roll 6 and a first nip roll 8, a second heat roll 5 is disposed on the opposite side of the first heat roll 6 while interposing the endless metallic belt 12 therebetween, a second nip roll 7 is disposed on the opposite side of the first nip roll 8 while interposing the endless metallic belt 12 therebetween, the first film 1 of a long shape is supplied to the space between the endless metallic belt 12 and the second heat roll 5, and the second film is layered on the first film 1 in such a portion that the first and second nip rolls 8, 7 are opposed to each other. When the endless metallic belt 12 is viewed from the outside thereof in the width direction, a portion of the endless metallic belt 12, which portion is located from a position between the first and second heat rolls 6, 5 to another position between the first and second nip rolls 8, 7, is extended in a straight line.

Description

  The present invention relates to a laminating apparatus for laminating a long second film on a long first film and a method for producing a laminated film.

  When laminating different types of films, particularly when the slack of the film is large, the application of tension prevents wrinkles and bubbles from occurring during laminating. In addition, in the case of bonding different types of films having greatly different tensile elastic moduli, there is a problem that internal stress remains at the film interface and curls occur.

  Patent Document 1 is a technique for correcting curl by absorbing moisture into a curled laminated film and curving the resin layer located inside the curled laminated film on the outside.

  However, there are many resin films that cause hydrolysis due to moisture or cracks or breaks due to bending, and it is desirable to prevent curling at the stage of bonding.

JP 58-33427 A

  In the case of using an ordinary dry lamination apparatus, the film is tensioned to prevent wrinkles and bubbles from occurring at the bonding interface, and the films are stretched and bonded together with the wrinkles extended. However, when the tensile modulus of elasticity of the films to be bonded is greatly different, the strain when the tension is applied differs depending on the film. Therefore, there is a problem that internal stress remains at the interface between the films and appears as curls. When the curl becomes large, it becomes difficult to handle, and there is a risk of subsequent product defects.

  An object of the present invention is to provide a laminating apparatus and a method for producing a laminated film that can prevent the occurrence of curling in bonding of films having different tensile elastic moduli.

  A laminating apparatus according to the present invention is a laminating apparatus for manufacturing a laminated film by laminating a long first film and a long second film, and is relatively upstream. A first heat roll disposed; a first nip roll disposed relatively downstream; an endless metal belt spanned between the first heat roll and the first nip roll; A second heat roll disposed on the opposite side of the first heat roll across the endless metal belt, and a second heat roll disposed on the opposite side of the first nip roll across the endless metal belt. A nip roll, wherein the first film is supplied between the endless metal belt and the second heat roll at a position where the first and second heat rolls are disposed, No. 2 nip roll In a portion facing the metal belt, the long first film and the second film are supplied between the endless metal belt and the second nip roll, and the first film When the endless metal belt is viewed from the outside in the width direction, from the position between the first and second heat rolls, the first and second films are laminated. The endless metal belt portion up to the position between the nip rolls is straight.

  In a specific aspect of the laminating apparatus according to the present invention, the laminating apparatus is further provided with a transport roll that is disposed relatively downstream of the second nip roll and on which the endless metal belt is stretched.

  In another specific aspect of the laminating apparatus according to the present invention, when the endless metal belt is viewed from the outside in the width direction, the position spanned by the transport roll from the position between the first and second heat rolls. The endless metal belt portion up to is straight.

  In the laminating apparatus according to the present invention, a winding roll for winding the laminated film formed by laminating the second film on the first film on the downstream side of the first and second nip rolls is further provided. It may be provided.

  The manufacturing method of the laminated film which concerns on this invention is a manufacturing method of the laminated film using the lamination apparatus comprised according to this invention, Comprising: As a 1st elongate film, tensile elasticity modulus is 20-300 MPa, thickness 1 to 1000 μm, the first film having a softening point in the range of 50 ° C. to 170 ° C., and the second film having a tensile modulus of 3500 to 10,000 MPa and a thickness in the range of 1 to 1000 μm, When the softening point of the film is Ts (° C.), the temperature of the first and second heat rolls is in the range of Ts-30 ° C. to Ts-10 ° C.

  According to the laminating apparatus of the present invention, since the first film is thermocompression bonded to the linear portion of the endless metal belt, the bonding surface of the first film can be kept horizontal without applying tension to the first film. Therefore, it is possible to prevent the curling from occurring when the first and second films are bonded.

It is the schematic of the laminating apparatus of this invention.

  Hereinafter, specific embodiments of the present invention will be invented with reference to the drawings.

  A laminating apparatus according to an embodiment of the present invention will be described with reference to FIG. The laminating apparatus of the present embodiment is a laminating apparatus that manufactures a laminated film 3 by laminating a first film 1 and a second film 2. The first film 1 and the second film 2 are both long films. Further, the first film 1 and the second film 2 are different. More specifically, the tensile elastic modulus of the first film is different from the tensile elastic modulus of the second film. Preferably, the first film 1 has a tensile elastic modulus of 20 to 3000 [MPa], a thickness of 1 to 1000 [μm], and a softening point of 50 to 170 [° C.], and the second film 2 has a tensile elastic modulus of 3500 to 10,000. [MPa], thickness 1 to 1000 [μm].

  But the tensile elastic modulus of the 1st, 2nd films 1 and 2 bonded by the laminating apparatus of this embodiment is not limited to the said specific tensile elastic modulus range and thickness range.

  The tensile elastic modulus of the film is a value measured according to JIS K 7161.

  Note that an adhesive or a pressure-sensitive adhesive is applied to the second film 2 in order to bond the second film 2 to the first film 1.

The adhesive and pressure-sensitive adhesive applied to the second film 2 are not particularly limited as long as the first film and the second film can be bonded together, and are acrylic resin, ionomer resin, urethane resin, Common things, such as an epoxy resin and an ethylene vinyl acetate copolymer resin, can be used.

  The method for applying the adhesive and the pressure-sensitive adhesive is not particularly limited as long as the method can apply the adhesive and the pressure-sensitive adhesive to the second film. For example, the microgravure coating method, the gravure coating method, Examples thereof include a bar coating method, a roll coating method, a wire bar coating method, a flexographic printing method, an offset printing method, and a screen printing method.

  As shown in FIG. 1, the laminating apparatus of this embodiment has an endless metal belt 12. The endless metal belt 12 is stretched between the first heat roll 6, the first nip roll 8, the transport roll 9, and the heat roll 10. The transport roll 9 is connected to a rotation drive source (not shown). The transport roll 9 is driven to rotate in the direction of the arrow shown in the figure. On the other hand, the 1st heat roll 6, the 1st nip roll 8, and the heat roll 10 are provided rotatably. When the transport roll 9 is rotated in the direction indicated by the arrow, the endless metal belt 12 is moved in the direction indicated by the arrow A. As a result, the first heat roll 6, the first nip roll 8, and the heat roll 10 are rotated in the rotation direction as indicated by the illustrated arrows.

  The first nip roll 8 is disposed on the relatively downstream side of the first heat roll 6. A second heat roll 5 is arranged on the opposite side across the first heat roll 6 and the endless metal belt 12. A second nip roll 7 is disposed on the opposite side of the first nip roll 8 and the endless metal belt 12.

  In the present embodiment, the transport roll 4 is disposed on the upstream side of the first and second heat rolls 6 and 5. The transport roll 4 is provided for transporting the first film 1 and supplying it between the first and second heat rolls 6, 5.

  A take-up roll 11 is disposed on the downstream side of the transport roll 9. The winding roll 11 winds up the laminated film 3 described later. Accordingly, the take-up roll 11 is connected to a drive source (not shown) and is driven to rotate in the direction of the arrow shown.

  The laminating apparatus of this embodiment is characterized in that the endless metal belt 12 has at least a portion from the position between the first and second heat rolls 6 and 5 to the position between the first and second nip rolls 8 and 7. The endless metal belt 12 is straight when viewed from the outside in the width direction. Here, the width direction of the endless metal belt 12 refers to a direction orthogonal to the direction in which the endless metal belt 12 is conveyed.

  The position of the transport roll 9 is not limited to the illustrated position, and the transport roll 9 can be arranged at any position as long as the endless metal belt 12 can be tensioned so that the endless metal belt 12 can be transported. .

  However, preferably, the endless metal belt 12 extends from the portion located between the first and second heat rolls 6 and 5 to the conveyance roll 9 beyond the first and second nip rolls 8 and 7. It is preferable that the portion is linear when viewed from the outside in the width direction. In that case, it is possible to prevent the film from being stretched due to the diameter of the nip roll 8, and to further enhance the curl prevention effect.

The heat roll 10 is provided to reheat the temperature of the endless metal belt 12 conveyed from the first heat roll 6 via the first nip roll 8 and the conveyance roll 9. By providing the heat roll 10, the temperature of the endless metal belt 12 can be made substantially equal to the temperature of the first and second heat rolls 6, 5 prior to contacting the first heat roll 6. But the heat roll 10 does not necessarily need to be provided.

  The first heat roll 6 and the second heat roll 5 are heated to the same temperature by a heat source (not shown). But the temperature of the 1st heat roll 6 and the 2nd heat roll 5 does not need to be equal.

  In the laminating apparatus of the present embodiment, the long first film 1 that is in contact with the transport roll 4 is supplied between the first and second heat rolls 6, 5, and the first and second nip rolls are supplied. It is conveyed between 8 and 7. That is, the first film 1 is supplied between the endless metal belt 12 that is in contact with the outer peripheral surface of the first heat roll 6 and the second heat roll 5. Thereby, the first film 1 is heated to the temperature of the first and second heat rolls 6 and 5 and a temperature close to the temperature. After that, the first film 1 is moved to a position facing the second nip roll 7 and the first nip roll 8 with the endless metal belt 12 sandwiched while maintaining the state of being temporarily press-bonded to the endless metal belt 12. Is done. In addition, in this invention, temporary press bonding means the state which can peel easily at the point of the conveyance roll 9 after roll conveyance.

  In the region where the first and second nip rolls 8 and 7 are opposed to each other, the second film 2 is laminated on the first film 1. In this case, since the first film 1 is preliminarily pressure-bonded to the endless metal belt 12 at the linear portion of the endless metal belt 12 and heated, the tension in the first film 1 is released and residual stress is eliminated. Can do. Therefore, the second film 2 is laminated on the first film 1 in a state where no tension is applied, that is, in a state where no internal stress is generated at the interface between the first film 1 and the second film 2. be able to. After that, the obtained laminated film 3 passes through the portion where the transport roll 9 is provided, and is taken up by the take-up roll 11.

  As described above, in the laminating apparatus according to the present embodiment, the endless metal belt 12 has the linear portion, and the first film 1 is thermocompression-bonded and conveyed to the endless metal belt 12 in the linear portion. . Therefore, the second film 2 can be laminated at a portion where the first and second nip rolls 8 and 7 face each other without applying tension to the first film 1. Therefore, even when the first film 1 and the second film 2 having different tensile elastic moduli are laminated, the occurrence of curling in the laminated film 3 can be reliably suppressed.

  Further, even after the first film 1 is pressure-bonded onto the endless metal belt 12, the elongation of the first film 1 due to the curvature of the first nip roll 8 hardly occurs. Therefore, peeling of the first film 1 from the endless metal belt 12 can be prevented, and elongation of the film due to the diameter of the first nip roll 8 can also be prevented.

  The thermal roll 10 is disposed upstream of the position where the first film 1 is temporarily thermocompression bonded to the endless metal belt 12. Accordingly, the endless metal belt 12 can be preliminarily heated upstream of the position where the first film 1 is temporarily pressure-bonded, so that the film 1 can be temporarily pressure-bonded efficiently. Moreover, since the temperature is lowered at the point of the transport roll 9, the laminated film 3 can be easily peeled off.

  The material of the endless metal belt 12 is not particularly limited, but is preferably carbon steel, nickel alloy, titanium, aluminum, copper, etc. that are excellent in thermal conductivity, flexibility, and heat resistance and are inexpensive, and the sleeve has a large thickness. The contact with the polyethylene cannot be heated, resulting in poor adhesion, and if it is thin, production becomes difficult.

If the temperature of the heat rolls 6 and 5 is too low, the adhesive force between the first film 1 and the endless metal belt 12 becomes low, which may lead to peeling before or during bonding. Moreover, when too high, the 1st film 1 will melt | dissolve, there exists a possibility that thickness may change at the time of temporary pressure bonding and bonding, and the film 1 may be damaged in a winding process. Therefore, the temperature of the heat rolls 6 and 5 is preferably 10 to 30 ° C. lower than the softening point Ts of the first film 1.

  The softening point Ts is measured according to JIS K 7196.

(Examples and comparative examples)
Next, examples of the present invention and comparative examples will be described. The present invention is not limited to the following examples.

  The laminating apparatus of the above embodiment was used to bond the first film and the second film. In addition, the kind of 1st film and the temperature of the heat roll were changed.

Example 1
A first film (material: polystyrene, manufactured by Mitsubishi Plastics, product number: Santo Clear, thickness 50 μm, tensile elastic modulus 2500 MPa, softening point 90 ° C.) and a second film (material: polyethylene terephthalate, manufactured by Mitsubishi Plastics, product number) : Diafoil, thickness 25 μm, tensile elastic modulus 5500 MPa, softening point 70 ° C.). In addition, the surface of the second film laminated on the first film was coated with an acrylic pressure-sensitive adhesive (manufactured by Shinsen Kogyo Co., Ltd., product number: HT-6537AM) to a thickness of 25 μm. . The temperature of the 1st, 2nd heat rolls 6 and 5 was set to 70 degreeC.

(Example 2)
A laminated film was obtained in the same manner as in Example 1 except that the temperature of the first and second heat rolls was set to 80 ° C.

Example 3
A laminated film was obtained in the same manner as in Example 1 except that the temperature of the first and second heat rolls 6 and 5 was set to 60 ° C.

Example 4
A first film (material: polyvinyl chloride, manufactured by Mitsubishi Plastics, product number: Vinica) having a thickness of 50 μm, a tensile modulus of 2500 MPa, and a softening point of 50 ° C., and a second film (material: 25 μm, a tensile modulus of elasticity of 5500 MPa) Polyethylene terephthalate, manufactured by Mitsubishi Plastics, product number: Diafoil) was bonded together. The temperature of the 1st, 2nd heat rolls 6 and 5 was set to 30 degreeC.

(Example 5)
A first film (material: polybutylene terephthalate, manufactured by Mitsubishi Plastics, product number: Novaduran) having a thickness of 50 μm, a tensile modulus of 2500 MPa, and a softening point of 170 ° C., and a second film (material: material: Novaduran) having a thickness of 25 μm. Polyethylene terephthalate, manufactured by Mitsubishi Plastics, product number: Diafoil) was bonded together. The temperature of the 1st, 2nd heat rolls 6 and 5 was set to 150 degreeC.

(Comparative Example 1)
A first film (material: polystyrene, manufactured by Mitsubishi Plastics, product number: Santo Clear) having a thickness of 50 μm, a tensile elastic modulus of 2500 MPa, and a softening point of 90 ° C., and a second film having a thickness of 25 μm and a tensile elastic modulus of 5500 MPa (material: polyethylene) Terephthalate, manufactured by Mitsubishi Plastics, product number: Diafoil). The temperature of the 1st, 2nd heat rolls 6 and 5 was set to 90 degreeC.

(Comparative Example 2)
A laminated film was obtained in the same manner as in Example 1 except that the temperature of the first and second heat rolls 6 and 5 was set to 50 ° C.

(Comparative Example 3)
A first film (material: polyvinyl alcohol, manufactured by Kuraray Co., Ltd., product number: Poval) having a thickness of 50 μm, a tensile elastic modulus of 2500 MPa, and a softening point of 40 ° C., and a second film (material: polyethylene terephthalate) having a thickness of 25 μm and a tensile elastic modulus of 5500 MPa , Manufactured by Mitsubishi Plastics, product number: Diafoil). The temperature of the 1st, 2nd heat rolls 6 and 5 was set to 20 degreeC.

(Comparative Example 4)
A first film (material: polyetherimide, manufactured by Mitsubishi Plastics, product number: Superior) having a thickness of 50 μm, a tensile elastic modulus of 2500 MPa, and a softening point of 180 ° C., and a second film having a thickness of 25 μm and a tensile elastic modulus of 5500 MPa ( Material: Polyethylene terephthalate, manufactured by Mitsubishi Plastics, product number: Diafoil) was bonded together. The temperature of the 1st, 2nd heat rolls 6 and 5 was set to 160 degreeC.

<Measure wrinkles>
A laminated film having a size of 100 mm × 100 mm is placed on a flat plane, and a quantity end in the TD direction is fixed with a tape. The height difference between the film surface and the lift in this state was measured. If this value was 3 mm or less, it was rated as ◯, and if it was greater than that, it was marked as x.

<Measurement of curl>
A laminated film having a size of 100 mm × 100 mm was placed on a flat plane, and the lifting height from the horizontal plane at the end was measured. If the amount of lift was 3 mm or less, it was rated as ◯, and if it was larger than that, it was marked as x.

<Measurement of peel strength>
The peel strength was measured by a method in accordance with the 180 ° C. peel test specified in JIS K 6854-2. If the peel strength was 1.0 to 3.0 N / cm, it was evaluated as “good”, otherwise it was set as “x”. .

DESCRIPTION OF SYMBOLS 1 ... 1st film 2 ... 2nd film 3 ... Laminated film 4 ... Conveyance roll 5 ... 2nd heat roll 6 ... 1st heat roll 7 ... 2nd nip roll 8 ... 1st nip roll 9 ... Conveyance roll DESCRIPTION OF SYMBOLS 10 ... Metal sleeve conveyance heat roll 11 ... Winding roll 12 ... Endless metal belt

Claims (5)

A laminating apparatus for producing a laminated film by laminating a long first film and a long second film,
A first heat roll disposed on the relatively upstream side, a first nip roll disposed on the relatively downstream side, and spanned between the first heat roll and the first nip roll. Endless metal belt,
A second heat roll disposed on the opposite side of the first heat roll across the endless metal belt;
A second nip roll disposed on the opposite side of the first nip roll across the endless metal belt,
The first film is supplied between the endless metal belt and the second heat roll at a position where the first and second heat rolls are disposed, and the first and second nip rolls are In the portion facing the endless metal belt, the long first film and the second film are supplied between the endless metal belt and the second nip roll, and the first film The second film is configured to be laminated on the film,
When the endless metal belt is viewed from the outside in the width direction, the endless metal belt portion from the position between the first and second heat rolls to the position between the first and second nip rolls is linear. Laminating equipment.   The laminating apparatus according to claim 1, further comprising a transport roll that is disposed on a relatively downstream side of the second nip roll and on which the endless metal belt is bridged.   When the endless metal belt is viewed from the outside in the width direction, the endless metal belt portion from the position between the first and second heat rolls to the position spanned by the transport roll is linear. The laminating apparatus according to claim 2.   The winding roll which winds up the laminated | multilayer film formed by laminating | stacking the said 2nd film on the said 1st film downstream from the said 1st, 2nd nip roll is further provided of Claims 1-3. The laminating apparatus of any one of Claims.   It is a manufacturing method of the laminated | multilayer film using the lamination apparatus of any one of Claims 1-4, Comprising: As a 1st elongate film, a tensile elasticity modulus is 20-300 MPa, thickness is 1-1000 micrometers, Using a first film having a softening point in the range of 50 ° C. to 170 ° C. and a second film having a tensile modulus of 3500 to 10,000 MPa and a thickness in the range of 1 to 1000 μm, the softening point of the first film The manufacturing method of a laminated | multilayer film which makes temperature of the 1st, 2nd heat roll the range of Ts-30 degreeC-Ts-10 degreeC, when is set to Ts (degreeC).

Images